Bruce -

The ZoneMaster II is basically the metering section of the Analyser Pro in a different box. It has the same functionality. The choice between an Analyser and the ZM/StopClock combo comes down to whether you want the additional flexibility of the StopClock's timer - i.e. programmable sequences and two channels. And to money of course :-)

The Analyser's timer does allow for burning-in exposures - it will automatically subtract the initial exposure time from subsequent exposures - but you can't set up a sequence in advance. The automatic safelight switching is available on the StopClock as well, and is convenient when making light measurements.